Selecting content items for presentation to a social networking system user in a newsfeed

摘要

To increase the likelihood of a user viewing content items previously identified for presentation but not viewed by the user, a social networking system accesses a view state associated with the user that identifies content items provided to the user and provided content items viewed by the user. Based on the view state, content items previously provided to the user but not viewed by the user are identified. Additional content items whose state has changed since presentation of the content items to the user are also identified. Content items previously presented to the user but not viewed with at least a threshold relevance to the user are ranked along with the additional content items. Based on the ranking, content items are selected for presentation to the user.